The values change only when my hand is between 10 and 15 cm. But in theory, this sensor (SHARP™ "GP2Y0A02YK") is supposed to detect 20 to 150 cm. Here is his datasheet : http://www.sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0a02_e.pdf

Thanks in advance for your help.

PS : If you need some more informations don't hesitate to ask me! I hope you understood my topic...

PS 2 : I have an official Arduino uno. The positive of the sensor is on the 5.5V on Arduino, The negative on de GND of Arduino and the Vo on the pin analog 1 on arduino.

The values change only when my hand is between 10 and 15 cm. But in theory, this sensor (SHARP™ "GP2Y0A02YK") is supposed to detect 20 to 150 cm.

Perhaps you did not read/understand from the data sheet that the 20 to 150 cm specification is for a very reflective piece of white paper and not for a hand, which does not reflect the IR as well as the white paper.

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